Oak Ridges Moraine Research Articles

Developing a lake management strategy by dovetailing lake monitoring with paleolimnological techniques: a case study from a kettle lake on the Oak Ridges Moraine (Ontario, Canada)

Moos MT, Ginn BK. 2016. Developing a lake management strategy by dovetailing lake monitoring with paleolimnological techniques: a case study from a kettle lake on the Oak Ridges Moraine (Ontario, Canada). Lake Reserv Manage. 32: 234–245.In response to concerns about declining water quality, increased aquatic plant biomass, and harmful algal blooms, a lake monitoring program was undertaken on a suburban kettle lake near Toronto, Canada. We identified environmental conditions consistent with eutrophication, and the largest source of phosphorus (P) loading was from sediment release during an extended period of low dissolved oxygen during thermal stratification of the water column. To put these current environmental conditions in perspective, account for long-term limnological trends, and develop a sustainable lake management strategy, we also undertook paleolimnological analysis of a sediment core. Using diatoms as proxy indicators, historic limnological conditions were reconstructed. Although pre-European settlement conditions were typical of lakes with forested catchments in this region, the lake was mesotrophic (total phosphorus [TP] ∼17.5 µg/L), likely from P bound to dissolved organic carbon. P concentrations increased with the use of chemical fertilizers and establishment of seasonal lakeside cottages and resorts starting in the 1920s (the beginning of the diatom-inferred (DI-) TP upward trend). With the conversion of these cottages into year-round homes (since 1960) and further urbanization of the catchment, including servicing with municipal water supply but continued reliance on septic tanks, P has increased further (TP ∼26.1 µg/L). For restoration to a sustainable state, methods of preventing sediment P release (capping the sediment surface or oxygenation of the hypolimnion) should be considered, along with installation of municipal wasterwater servicing and stewardship projects to prevent further P loading from septic systems and surface runoff.

A revised depositional setting for Halton sediments in the Oak Ridges Moraine area, Ontario

Outcrop and continuous core descriptions, high-resolution seismic profiling, and downhole geophysical data are integrated with detailed mapping to update sedimentary and stratigraphic frameworks for Halton sediment, a complex mud-rich lithofacies succession. Halton sediment has a gradational transition from underlying Oak Ridges Moraine (ORM) sediment and can abruptly overlie Newmarket Till. Halton strata thin and fine upwards from ORM sand and gravel to graded sand, silt, and clay rhythmites, with muddy diamicton and sand and gravel interbeds. These strata fill basin lows and drape ORM sediment lobes and Newmarket Till drumlins. These distinct sedimentary units are here informally referred to as Halton formation. Formal Halton Till is a proposed subunit of Halton formation, a clay-rich diamicton mapped from Niagara Peninsula to ORM and eastward. Halton Till has traditionally been inferred to represent a late, climatically induced readvance of grounded ice from Lake Ontario basin, which deposited drumlinized till. Halton sedimentary architecture and facies are interpreted as deposition in an ice-marginal or subglacial lake bounded by Niagara Escarpment, ORM, and grounding line oscillation of a semi-buoyant ice shelf or ice lid over Lake Ontario. Large volumes of transported mud are distal equivalents of ORM high-energy gravelly sand deposits to the east. Glaciolacustrine sedimentation is indicated by mud-rich texture and laminations. Clay–silt rhythmites, diamicton interbeds, and intraclasts indicate ponding, debris flow, and periodic ice loading. Halton depositional model may apply to other muddy diamictons in Great Lakes basins. Halton formation facies are not compatible with proposed grounded ice stream events in Lake Ontario basin.

Soil water recharge for grassed and forested land covers on the Oak Ridges Moraine, southern Ontario, Canada

Soil water recharge (R) below 1 m depth was estimated via a 1-d water balance for grasslands, hardwood stands and red pine plantations on the Oak Ridges Moraine (ORM) in southern Ontario, Canada. Annual R values (431–696 mm) were in the order of previous estimates for outcropping sands and gravels on the ORM (∼400 mm); however, they only partially supported hypothesized differences in R between land covers. Annual R was similar for grasslands and hardwood stands and exceeded that for red pine plantations. However, there were no consistent differences in R between land covers for growing or dormant seasons, due to relatively large uncertainties for R estimates as well as inter-site differences in the soil's ability to store and transmit inputs below 1 m. Nevertheless, shifts in annual R appear to have accompanied historical land cover changes from hardwood-conifer stands → agricultural fields → red pine plantations → regenerating hardwoods. Growing season R in hardwoods makes a larger contribution to total R than for other land covers, partly due to spatially focused throughfall and stemflow contributions to R. Results highlight the role of land cover differences when assessing spatial variations in R along the ORM.

Stemflow and throughfall contributions to soil water recharge under trees with differing branch architectures

AbstractTrees whose branches slope towards or away from the bole differ in the spatial pattern of water delivery to the soil surface beneath their canopies. This study examines the implications of these differences for soil water recharge below 1 m depth in a managed forest on the Oak Ridges Moraine in southern Ontario. Throughfall and vertical profiles of soil water content at varying distances from the boles of a sugar maple and two red pines of differing ages (36 and 57 years old) were measured during rainfall inputs in the summer of 2009 and in the spring/early summer of 2010. Stemflow fluxes were estimated using measurements on nearby trees with similar morphologies. A water balance approach was used to estimate recharge at each distance from the bole, as well as for the entire sampled area beneath each tree's canopy. Throughfall was more than 1.3 times above‐canopy rainfall within 0.5 m of the bole of the sugar maple, and stemflow volumes were at least an order‐of‐magnitude greater than those for the pines in both 2009 and 2010. These focused inputs resulted in greater near‐bole soil water contents and soil water recharge in excess of above‐canopy rainfall within 0.3 m of the sugar maple bole. In contrast, both young and old pines showed no significant trends in throughfall with distance from the bole, and minor stemflow volumes made insignificant contributions to recharge near the pine boles. Recharge was significantly greater than 0 beneath the canopy of all three trees in both years and was generally similar between trees. The exception was recharge beneath the sugar maple in 2010, which exceeded that of the young red pine as a result of the former's large stemflow fluxes. Results suggest the transition from red pine plantations to mixed hardwood‐conifer stands will not alter total soil water recharge during spring and summer rainfall inputs; nevertheless, it will generate marked changes in the spatial pattern of sub‐canopy recharge in this forest landscape on the Oak Ridges Moraine. Copyright © 2015 John Wiley & Sons, Ltd.

Spatiotemporal patterns of baseflow metrics for basins draining the Oak Ridges Moraine, southern Ontario, Canada

The Oak Ridges Moraine (ORM) is a key hydrogeologic feature in southern Ontario, supplying potable water along with important aquatic ecosystem services. Stream baseflow is a useful indicator of groundwater discharge to streams on the ORM and gives insight into the regional hydrogeologic system. This study examines how climatic and basin attributes explain spatiotemporal patterns in baseflow metrics for streams draining the ORM. Baseflow was separated from streamflow using an automated digital filter, and water-year baseflow and baseflow as a fraction of precipitation and total streamflow (baseflow index, BFI) were determined. Much of the variability in baseflow metrics was explained by such characteristics as water-year precipitation, mean basin slope, spatial extent of outcrops of permeable sands and gravels, and forest and urban cover. Identified thresholds for basins with above- or below-average baseflow and BFI could serve as a screening tool in resource management decisions on the ORM. Precipitation has increased for many basins in the latter part of the twentieth and early part of the twenty-first century, often accompanied by greater baseflow. The rate of baseflow increase was related to the spatial extent of sand and gravel outcrops, implying a nonuniform response of baseflow to rising precipitation for basins across the ORM. Although baseflow from these basins may continue to increase under the wetter climate predicted for southern Ontario in the twenty-first century, such forecasts must consider the role of land-use change (e.g. forest expansion, urban development) in altering the partitioning of precipitation between direct runoff and baseflow contributions to streamflow.La moraine Oak Ridges (ORM) est une caractéristique hydrogéologique importante dans le sud de l’Ontario fournissant en eau potable et délivrant de nombreux services pour l’écosystème aquatique. Le débit de base des cours d’eau est un indicateur important de l’écoulement des eaux souterraines dans l’ORM et donne un aperçu du système hydrogéologique régional. Cette étude examine l’influence des caractéristiques climatiques et les propriétés du bassin versant sur les variations spatio-temporelles des débits de base des cours d’eau drainants l’ORM. Le débit de base a été séparé du débit d’eau à l’aide d’un filtre numérique automatisé alors que le débit de base eau annuel, le débit de base sous forme de précipitation et le débit total (débit de base indice, BFI) ont été déterminés expérimentalement. Une grande partie de la variabilité des mesures de débit de base s’expliquait par les précipitations annuelles, la pente moyenne du bassin, l’étendue spatiale des affleurements de couches perméables de sable et gravier, et du couvert forestier et urbain. Les seuils identifiés pour les bassins avec débit de base supérieur ou inférieur au débit de base moyen et BFI pourraient servir d’outil de dépistage dans les décisions de gestion des ressources pour l’ORM. Au cours des dernières décennies, les précipitations ont augmenté dans de nombreux bassins versants et elles ont souvent été accompagnées par de grands débits de base. Les taux d’augmentation du débit de base étaient associés à l’étendue spatiale des affleurements de sable et de gravier, impliquant une réponse non uniforme du débit de base vers la hausse des précipitations pour les bassins à travers l’ORM. Bien que le débit de base de ces bassins pourrait continuer à augmenter avec un climat plus humide comme prédit pour le sud de l’Ontario au vingt-et-unième siècle, les prévisions de débit de base devraient considérer le rôle du changement d’affectation des terres telle que l’expansion des forêts et le développement urbain, et modifier le cloisonnement des précipitations entre ruissellement direct et contribution du débit de base au débit d’eau.

Stemflow and soil water recharge during rainfall in a red pine chronosequence on the Oak Ridges Moraine, southern Ontario, Canada

Summary Stemflow focusses water delivery to the forest floor in a relatively small area surrounding the tree bole, with the potential to enhance soil water contents and water recharge relative to more distal sites beneath the canopy. These stemflow fluxes may decrease as a given tree species ages due to changes in branch orientation and bark roughness, suggesting that the relative contribution of stemflow to water recharge near the bole will decline with time. The hypothesis that stemflow fluxes decline with tree age was tested in a chronosequence of red pine ( Pinus resinosa Ait.) stands in a managed forest in southern Ontario, Canada, and stemflow contributions to soil water recharge below 1 m depth were quantified. Throughfall, stemflow and sub-canopy soil water contents (0.1 m and 1.5 m from the tree bole to 1 m depth) in stands ranging from 28 to 80 years in age were studied from late-Spring to Fall in 2012, supplemented by artificial irrigations of stemflow to examine short-term soil wetting at the two distances from the bole. The hypothesized decline in stemflow with increasing tree age was not supported, and canopy cover variations and forest management exerted a greater control on inter-stand differences in stemflow fluxes. Stemflow contributions generally resulted in greater soil water recharge below 1 m depth at 0.1 m from the tree bole compared to the 1.5 m distance. This enhanced recharge was greatest for the youngest stand and differences in recharge between the 0.1 m and 1.5 m distances from the bole were likely not significant for stands between 40 and 80 years of age. Nevertheless, the relative contribution of stemflow to soil water recharge may increase in this managed forest as red pine stands give way to a mixed hardwood-conifer forest, due to greater stemflow fluxes from hardwood species in this landscape.

Groundwater knowledge management for southern Ontario: An example from the Oak Ridges Moraine

The interest surrounding groundwater protection in Southern Ontario has grown considerably since the Walkerton tragedy of May 2000. Since that time, a number of technical studies have been undertaken by the Province to support the preparation of Source Water Protection plans. Underlying all sound water resource management initiatives in Ontario is the need for a renewed focus on the fundamentals, specifically in this case a focus on groundwater knowledge and its management. Using the Oak Ridges Moraine Hydrogeology Program as a unique example of a groundwater “knowledge management” system, this paper presents some unexplored opportunities that merit further consideration in the application of a “knowledge management” philosophy within Ontario’s overall water management framework. Within the Program’s study area, the linkage and integration of the Water Well Information System with other borehole datasets and consulting reports, as well as with water use (e.g. municipal pumping) and water quality databases, has created perhaps the most comprehensive, actively managed groundwater “knowledge management” system in Canada. Ongoing Source Water Protection and other work undertaken through consultants, including data and geological/hydrogeological interpretations, is being re-incorporated, where sound and appropriate, into the program’s existing groundwater knowledge infrastructure. The program’s groundwater “knowledge management” system has been developed with a long-term (i.e. multi-decade) water management time frame in mind and is made accessible to geoscientists undertaking work in the area.

Sustainability and suburban housing in the Toronto region: the case of the Oak Ridges Moraine Conservation Plan

This article focuses on the relationship between housing and sustainable development in the suburban portion of the Toronto-centered region. Interviews with key stakeholders were completed to examine the implementation of the Oak Ridges Moraine Conservation Plan by the Canadian province of Ontario as a response to the negative impacts associated with single-family detached housing development. Representatives from government, real estate development, and the non-profit sector were asked to identify the housing characteristics they considered relevant for achieving sustainable development objectives. The responses indicate that achieving a consensus among stakeholders requires addressing a diverse set of perspectives related to environmental, economic, land-use planning, and social issues. A final section discusses the impacts of Ontario’s Greenbelt Act and the Growth Plan for the Greater Golden Horseshoe on the link between housing and sustainability.

The Oak Ridges Moraine as a Social Innovation: Strategic Vision as a Social-Ecological Interaction

McCarthy, D. D. P., G. S. Whitelaw, F. R. Westley, D. D. Crandall, and D. Burnett. 2014. The Oak Ridges Moraine as a social innovation: strategic vision as a social-ecological interaction. Ecology and Society 19(1): 48. https://doi.org/10.5751/ES-06212-190148

Satellite Monitoring of Urban Sprawl and Assessment of its Potential Environmental Impact in the Greater Toronto Area Between 1985 and 2005

This research investigates urban sprawl in the Greater Toronto Area (GTA) between 1985 and 2005 and the nature of the resulting landscape fragmentation, particularly with regard to the Oak Ridges Moraine (ORM), an ecologically important area for the region. Six scenes of Landsat TM imagery were acquired in summer of 1985, 1995, and 2005. These images and their texture measures were classified into eight land cover classes with very satisfactory final overall accuracies (93-95%). Analysis of the classifications indicated that urban areas grew by 20% between 1985 and 1995 and by 15% between 1995 and 2005. Landscape fragmentation due to spatio-temporal land cover changes was evaluated using urban compactness indicators and landscape metrics, and results from the latter were used to draw conclusions about probable environmental impact. The indicator results showed that urban proportions increased in nearly all areas outside of the metropolitan center, including on portions of the ORM. The landscape metrics reveal that low density urban areas increased significantly in the GTA between 1985 and 2005, mainly at the expense of agricultural land. The metric results indicate increased vulnerability and exposure to adverse effects for natural and semi-natural land cover through greater contrast and lowered connectivity. The degree of urban perimeter increased around most environmentally significant areas in the region. Changes like these negatively impact species and the regional water supply in the GTA. Further investigation into specific environmental impacts of urban expansion in the region and which areas on the ORM are most at risk is recommended.

Measurement and modeling of canopy water partitioning in a reforested landscape: The Ganaraska Forest, southern Ontario, Canada

Summary A major hydrologic consequence of reforestation is an increase in canopy interception ( I c ), with consequent effects on such processes as soil and groundwater recharge. This study examines the change in rainfall partitioning between throughfall ( TF ), stemflow ( SF ) and I c in red pine plantations of different ages and in mature mixed hardwood forest stands in the Ganaraska Forest on the crest of the Oak Ridges Moraine in southern Ontario. It also tests the ability of the Liu interception model to predict I c in these stands. Forest characteristics, TF , SF and I c were either measured or estimated during the 2009 and 2010 growing seasons for three red pine stands 36–41 years old (as of 2009), three red pine stands 57–62 years old, and three mixed hardwood stands 74–107 years old. Despite considerable variability in total I c in a given stand type in both years, there was a general increase in I c as a fraction of above-canopy precipitation ( P g ) from younger to older red pine stands and to mixed hardwood stands. This was accompanied by a decrease in SF depth as a fraction of P g from younger to older red pine stands, followed by an increase in SF / P g in mixed hardwoods. The Liu model provided good predictions of I c in 2009 for eight of nine stands with canopy storage capacities optimized using the 2009 data. Model performance was almost as good when tested against the 2010 data using the 2009 model parameters. Adjustment of the parameter representing the ratio of mean evaporation rate to mean rainfall rate to account for greater evaporative demand in 2010 led to a modest improvement in model performance. The increase in growing season I c / P g ratios as red pine plantations in the Ganaraska Forest mature and undergo a managed transition to mature mixed hardwoods may have important implications for soil water and groundwater recharge that require further study. The Liu model is a promising means of estimating I c in forest stands of differing age and type, which in turn will assist in understanding the hydrologic consequences of reforestation in this landscape.

The paleolimnology of Haynes Lake, Oak Ridges Moraine, Ontario, Canada: documenting anthropogenic and climatic disturbances

Haynes Lake is a small kettle lake located on the Oak Ridges Moraine, and is within the Greater metropolitan area of Toronto, Ontario; Canada’s most populous region. Lake sedimentation, flux rates, diatoms and thecamoebians extracted from a benthic core were used as biological proxies to evaluate changes in water quality through time as a function of anthropogenic activity and changing climate. There were two periods of disturbance to the Haynes Lake ecosystem from ca 8,500 years before present (YBP) through to ca A.D. 2003, which were significant enough to cause changes in lake sedimentation, the diatom flora, and thecamoebian fauna. The first disturbance was concomitant with the decline in global temperatures following the Hypsithermal Climate Optimum (ca. 4,700 YBP). The most significant disruption to Haynes Lake over the last 8,500 years, however, was the settlement of Europeans and subsequent urban development (ca. A.D. 1875), including the construction of a road immediately adjacent to the lake. Anthropogenic disturbance of inorganic clays in the recent paleosediment record (<5 cm) is indicative of more recent eutrophication events.

Development of an Arcellacea (testate lobose amoebae) based transfer function for sedimentary Phosphorus in lakes

Arcellacea (testate lobose amoebae) communities were assessed from 73 sediment-water interface samples collected from 33 lakes in urban and rural settings within the Greater Toronto Area (GTA), Ontario, Canada, as well as from forested control areas in the Lake Simcoe area, Algonquin Park and eastern Ontario. The results were used to: (1) develop a statistically rigorous arcellacean-based training set for sedimentary phosphorus (Olsen P (OP)) loading; and (2) derive a transfer function to reconstruct OP levels during the post-European settlement era (AD1870s onward) using a chronologically well-constrained core from Haynes Lake on the environmentally sensitive Oak Ridges Moraine, within the GTA. Ordination analysis indicated that OP most influenced arcellacean assemblages, explaining 6.5% (p<0.005) of total variance. An improved training set where the influence of other important environmental variables (e.g. total organic carbon, total nitrogen, Mg) was reduced, comprised 40 samples from 31 lakes, and was used to construct a transfer function for lacustrine arcellaceans for sedimentary phosphorus (Olsen P) using tolerance downweighted weighted averaging (WA-Tol) with inverse deshrinking (RMSEPjack-77pp; r2jack=0.68). The inferred reconstruction indicates that OP levels remained near pre-settlement background levels from settlement in the late AD 1970s through to the early AD 1970s. Since OP runoff from both forests and pasture is minimal, early agricultural land use within the lake catchment was as most likely pasture and/or was used to grow perennial crops such as Timothy-grass for hay. A significant increase in inferred OP concentration beginning ~AD 1972 may have been related to a change in crops (e.g. corn production) in the catchment resulting in more runoff, and the introduction of chemical fertilizers. A dramatic decline in OP after ~AD 1985 probably corresponds to a reduction in chemical fertilizer use related to advances in agronomy, which permitted a more precise control over required fertilizer application. Another significant increase in OP levels after ~AD 1995 may have been related to the construction of a large golf course upslope and immediately to the north of Haynes Lake in AD 1993, where significant fertilizer use is required to maintain the fairways. These results demonstrate that arcellaceans have great potential for reconstructing lake water geochemistry and will complement other proxies (e.g. diatoms) in paleolimnological research.

The Ontario Greenbelt: Shifting the Scales of the Sustainability Fix?*

The government of Ontario, Canada, has passed legislation to protect large parts of the southern portions of the province from most development. An extensive plan for a Greenbelt that surrounds the Greater Toronto Area and other regional growth centers was introduced. This article looks at the new policy as a spatial strategy that shifts the scales of environmental and growth management policy in Ontario. The legislation also sets the framework for a state spatial project; that is, a set of changes in how the regional state internally operates. The current Greenbelt legislation is a new step in a longer term development by which governments in Ontario have attempted to regulate the relationships between cities and regions, town and hinterland. Overlapping strongly with what is usually called the Toronto bioregion between the Niagara Escarpment, Oak Ridges Moraine, and Lake Ontario, the Greenbelt reorganizes space in southern Ontario in ways that would further ecosystem policies and practices in the area. Theoretically guided by newer debates on rescaling and regionalism, and based on close reading of the planning and policy documents on the Greenbelt as well as a series of expert interviews, we argue that the current Greenbelt legislation is an act of up-scaling traditional urban-regional regulation in southern Ontario, which we shall call extended metropolitanization. Such rescaling recasts traditional political conflicts in new terms. We conclude that extended metropolitanization in southern Ontario has been a process that has brought nature, the state, and governance together into a new regional sustainability fix.

Reaping Nature's Dividends: The Neoliberalization and Gentrification of Nature on the Oak Ridges Moraine

In this article, we follow the position that neoliberalism is not a state but a process of political, social, and economic development. We explore the neoliberalization of nature in the exurban region of a rapidly expanding metropolitan conurbation, the Greater Toronto Area in Ontario, Canada. Since 2001, the Oak Ridges Moraine legislation has been in place to halt urban sprawl and conserve the nature of a regionally significant landform. Our analysis suggests that the Oak Ridges Moraine legislation is consistent with neoliberalization but that the process needs to be seen in the context of half a century of rural and exurban gentrification. Longstanding class privilege is perpetuated through the aegis of legislation to preserve nature and protect the countryside. The legislation aestheticizes the Moraine as a unique landform, complements private-based conservation efforts, and voluntary policy initiatives, as well as marketizes the Moraine as a desirous place where wealthy residents reap nature's dividends. This analysis confirms the usefulness of neoliberalism as a concept, but suggests that it needs to be explored through a historically and place-based informed perspective. The case study also sheds light on nature's role in state action, and the rallying and shaping of a regional nature to support state power.

Incremental planning and land-use conflict in the Toronto region's Oak Ridges Moraine

The Greater Toronto Area is the largest urban concentration in Canada and one of the most significant built regions in North America. Toronto's growth legacy has created a legacy of sprawl development. Growth has not occurred without controversy. On the Oak Ridges Moraine, an environmentally sensitive landform located along Toronto's northern suburban edge, development has been the catalyst for activism and policy changes that led to a fundamental rethinking of Ontario's planning regime. Changes to Ontario's planning approach have resulted in land-use conservation legislation to manage development activity on the Moraine. This paper considers the role of incremental policies in creating a conflict setting which ultimately led to ecologically based planning legislation. We conclude that several factors helped advance conservation planning – media attention, a history of incremental planning, the emergence of a well-organised conservation movement and the serendipitous convergence of key leadership personalities.

Characterization of peak flow events with local singularity method

Abstract. Three methods, return period, power-law frequency plot (concentration-area) and local singularity index, are introduced in the paper for characterizing peak flow events from river flow data for the past 100 years from 1900 to 2000 recorded at 25 selected gauging stations on rivers in the Oak Ridges Moraine (ORM) area, Canada. First a traditional method, return period, was applied to the maximum annual river flow data. Whereas the Pearson III distribution generally fits the values, a power-law frequency plot (C-A) on the basis of self-similarity principle provides an effective mean for distinguishing "extremely" large flow events from the regular flow events. While the latter show a power-law distribution, about 10 large flow events manifest departure from the power-law distribution and these flow events can be classified into a separate group most of which are related to flood events. It is shown that the relation between the average water releases over a time period after flow peak and the time duration may follow a power-law distribution. The exponent of the power-law or singularity index estimated from this power-law relation may be used to characterize non-linearity of peak flow recessions. Viewing large peak flow events or floods as singular processes can anticipate the application of power-law models not only for characterizing the frequency distribution of peak flow events, for example, power-law relation between the number and size of floods, but also for describing local singularity of processes such as power-law relation between the amount of water released versus releasing time. With the introduction and validation of singularity of peak flow events, alternative power-law models can be used to depict the recession property as well as other types of non-linear properties.

Building bioregional citizenship: the case of the Oak Ridges Moraine, Ontario, Canada

In the last 20 years, the Oak Ridges Moraine in Toronto's metropolitan region has changed from a scarcely mentioned landscape feature into an environmental icon for residents and environmentalists and a conservation object for the provincial government. In efforts to save the Moraine from urban sprawl, the concepts of bioregion and bioregionalism have been invoked to create a suburban/exurban defence of non-human nature and to promote an ethic of place. We identify three dominant currents of bioregionalism: ecocentrism (a concern for the intrinsic value of non-human nature), scientific managerialism (focused on the setting aside of natural areas), and socio-environmental considerations (centring on environmental justice). We note that invocations of ecocentrism and science are NIMBYist or shallow, and references to environmental justice issues are absent. We conclude that a concept of bioregional citizenship that sees beyond a physically defined bioregion recognises the emotional ties people feel beyond their immediate living space, and includes environmental justice as a useful concept to advance the bioregionalist agenda.

Producing regionalism: regional movements, ecosystems and equity in a fast and slow growth region

Urban development pressures, preservation of environmentally sensitive areas and regional planning are the focus of current debates on regionalism in both fast and slow growth regions. Based on two cases—a campaign to preserve ecological integrity and reduce sprawl on the Oak Ridges Moraine in the Greater Toronto Area and Rochester’s anti-sprawl campaign for regional equity—the paper examines how two anti-sprawl campaigns brought to the fore alternative constructions of regionalism. In the fast growing Toronto region, citizen mobilization and upper tier intervention resulted in a legislative base for regionalism. In the slow growth Rochester region, the city had limited success in gaining regional redistribution. Such divergent outcomes relate to differences in intergovernmental relations, the city’s influence on the region, receptivity of suburbs to smart growth, and the potential for values of nature preservation and justice to mobilize regional coalitions.

Estimating Summer Low-Flow in Streams in a Morainal Landscape using Spatial Hydrologic Models

This study evaluated the capability of four spatial hydrologic models to estimate summer low-flow stream discharge, as a surrogate for baseflow, and assessed the influence of land cover/land use on these flows, in small streams across the Oak Ridges Moraine. Low-flow discharge varied predictably with area of the upstream catchment, but also with reach slope and a measure of land cover disturbance (LDI). Low-flow volumes were lowest in streams with moderate agricultural and/or urban development (LDI of eight to 12%), and high over a range of development intensities. Each of Baseflow Index (BFI×Area), Darcy Index (DI), MODFLOW (MF) and a finer resolution MODFLOW model (FMF) were about equal in their capability to estimate low-flow discharge, with MF and FMF having a somewhat stronger relationship and Darcy Index having a somewhat poorer relationship, particularly in smaller catchments. Each of the models generally predicted low-flow discharge volumes to within about 400 L/s of the actual observed low-flow discharge. The models, therefore, were generally unable to predict whether a stream was flowing during periods of low-flow when the upstream catchment was smaller than about 17,800 ha. It was found that these methods cannot be reliably applied in small catchments as there is too much natural variability in flow conditions. This paper suggests that these methods do not reflect local conditions, but rather provide generalized information about water flows. As a result, it is recommended that until spatial model predictions are improved for local applications, water managers should invest in field surveys to confirm flow conditions in small catchments.